FastProxy: Hardware and Software Acceleration of Stratum Mining Proxy

The Stratum protocol is the de facto protocol for mining proxies in proof-of-work (PoW) based cryptocurrencies such as Bitcoin. A Stratum mining proxy connects to an upstream mining pool server and to downstream miners through TCP/IP connections. The proxy receives periodic jobs from the pool and broadcasts them to the miners. The broadcast operation becomes a performance and scalability bottleneck when the number of miners increases significantly. In this paper, we propose a hardware/software co-designed architecture for the proxy to accelerate the broadcast of periodic jobs. We customize the Stratum protocol with a layer 2 broadcast mechanism instead of using TCP/IP connections. The proposed architecture is implemented on a Xilinx Zynq SoC (ARM processor and FPGA) board where the layer 2 broadcast mechanism is offloaded on the FPGA. Our experiments demonstrated a speedup of 2079x in transmission time with 225 miners connected to the proxy, compared to an implementation on an Intel i7 server.